RESEARCH a Riparian Wildlife Habitat

RESEARCH DOI: 10.1007/s002670010249 A Riparian Wildlife Habitat Evaluation Scheme Developed Using GIS LOUIS R. IVERSON* ual streams (for acquisition or management) by habitat rank- USDA Forest Service ing. We demonstrate this methodology for the Vermilion River Northeastern Research Station basin in east-central Illinois, USA. Three data sets were used 359 Main Road to evaluate land cover encompassing 300 m on either side of Delaware, Ohio 43015, USA the streams: (1) the US Geological Survey’s land use and land cover information (LUDA), (2) land cover manually digitized DIANE L. SZAFONI from the National High Altitude Photography (NHAP) program, Geographic Modeling Spatial Laboratory and (3) Landsat Thematic Mapper (TM) data classified into University of Illinois at Urbana-Champaign land cover. Each of 30 tributaries in the study area was 220 Davenport Hall ranked for habitat according to the data contained in each Urbana, Illinois 61801, USA data set, and results were compared. Habitat ranking schemes were devised and analysis performed for three spe- SHARON E. BAUM cies guilds: forest, grassland, and mixed successional spe- Illinois Natural History Survey cies. TM and NHAP each differentiated habitat scores (for for- 607 East Peabody est, grassland, and mixed successional guilds) among Champaign, Illinois 61820, USA tributaries in a similar and suitable way, while LUDA was not suitable, due to the coarse resolution of the data. Overall, it ELIZABETH A. COOK was shown that the methodology is suitable to rank streams USDA-Natural Resources Conservation Service at Lincoln based on riparian habitat quality. Even though more work is University needed to test and verify the method, the project has shown 306 Founders Hall the potential for such techniques to assist in evaluating, track- Jefferson City, Missouri 65102, USA ing, and improving the management of riparian wildlife resources. The method can easily be applied over large areas ABSTRACT / To evaluate riparian habitat for wildlife, we used such as states if TM-based land cover and stream data are a geographic information system (GIS) that prioritized individ- available. In the late 1970s, the President’s Council on Envi- (Hanson et al. 1990, Harris and Scheck 1991), sinks, ronmental Quality (1978) estimated that as much as and sources. 70% of riparian ecosystems (systems adjacent to Illinois is a highly developed state with less than 11% streams and rivers) present at the time of European of its area in its “potential” vegetation type (Klopatek et colonization in the United States had been destroyed. al. 1979). Although large in size (142,000 km2), agri- Presently, evidence continues to mount on the ex- culture and urbanization dominate the state, and only tremely high value that riparian systems provide in a small percentage of the state can be considered high ecosystem services (Forman 1995); protection of water quality for wildlife (Iverson et al. 1989). Illinois con- quality as filters (Welsch 1991, Gilliam 1994), biodiver- tains in excess of 21,200 linear km of streams and rivers sity/habitat (Naiman et al. 1993), conduits for dispersal (Neely and Heister 1987). The majority is characterized by their low gradient and was historically connected to KEY WORDS: Landscape ecology; Riparian habitat; Wildlife habitat; expansive floodplain areas of high-quality wetland, for- GIS; Illinois; Spatial analysis est, and grassland habitats. Subsequent channelization, artificial draining, and leveeing effectively isolated the *Author to whom correspondence should be addressed; email: fertile floodplain from the stream channels leading to [email protected]. the decimation of much of the native habitats through- 1 The use of trade, firm, or corporation names in this publication is for out the state (e.g., Osborne et al. 1991). Similar, or the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the US Department even greater losses of forests and wetlands have been of Agriculture or the Forest Service of any product or service to the documented across Illinois (Iverson and Risser 1987; exclusion of others that may be suitable. Iverson et al. 1989, Havera and Suloway 1994), and land Environmental Management Vol. 28, No. 5, pp. 639–654 © 2001 Springer-Verlag New York Inc. 640 L. R. Iverson and others conversion continues, especially in the south-central scribed here. By incorporating a spatial component portion of the state (Osborne et al. 1991, Iverson 1994). into the data sets, the IGIS made it possible to combine The loss of wildlife habitat has been documented in and compare various data sets, evaluate the character- Illinois and has reached a critical stage (Illinois Wildlife ization of streams relative to wildlife habitat, and gen- Habitat Commission 1985, Havera and Suloway 1994). erate maps and tabular data for statistical analysis and Remaining riparian areas comprise a significant por- display. Several data sets were available for analysis and tion of the remnant forested vegetation in the state. In evaluation (Table 1). fact, for the south-central portion of the state, 79% of Many of the data sets used in the study are subsets of the forest land is within 300 m of the streams (Iverson larger, statewide coverages. Others are regional, cover- 1994). This pattern is primarily due to residuals remaining only the Vermilion basin, as in this investigation. ing because of the historical difficulty of growing row Data sets differ in scale, temporality, and in the degree crops economically on the steeper slopes associated of processing that is necessary to use them. All images with many of the stream and river valleys (Iverson (photographic or satellite) were based on data col- 1988). Thus, information on the location and extent of lected within a decade, 1978–1988, to minimize tem- these important vestiges of native Illinois is critical for poral variation. This basin is largely rural and is not the successful management and protection of riparian undergoing rapid urbanization relative to some other habitats. In Illinois, this is complicated not only by the parts of the state and country. Different coding state’s size, but also by the geographical variability that schemes were normalized so that data generated exists from north to south, and most importantly, by through spatial processing of the various data sets could economic constraints. It is imperative that resource be statistically compared. managers maximize the use and application of infor- Land and Stream Data Set Description and mation that may reside in statewide databases to iden- Derivation tify these vital riparian habitats. The objectives of this study were to: (1) identify riparian wildlife habitats Digital line graph. Primary among the digital carto- along streams in the Vermilion River basin located in graphic products produced by the US Geological Ser- east-central Illinois using applicable and available data vice (USGS) are the digital line graph (DLG) files sources; (2) develop and assess methodologies to iden- (Table 1). The 1:100,000-scale hydrographic layer of tify riparian habitats of different qualities in the Ver- the DLG files for all of Illinois resides on the IGIS and milion River basin using these data sources; and (3) comprises the most detailed representation of the compare the results of these methods to identify quality streams and lakes available for the whole state. The riparian wildlife habitats throughout the state and be- USGS produced these data by digitizing a photograph- yond. ically reduced composite of the hydrographic layer from the 1:24,000 USGS base map series. The data carry codes identifying the type of feature represented, such Materials and Methods as stream or shoreline and descriptive information such as flow (for example, intermittent) or spatial location Study Area (for example, right bank) (US Department of the In- This study was conducted on the Salt Fork and Mid- terior and US Geological Survey 1989). dle Fork branches of the Vermilion River (tributary to The data pertinent to the study area were extracted the Wabash River) located in east-central Illinois (Fig- and modified for use in this project. This effort in- ure 1). Within these watersheds, a total of 30 streams volved edge matching to make the data topologically drain an area of at least 10 sq mi (25.8 km2). The consistent and then extracting only those streams with Vermilion River basin has a long history of scientific at least 10 square miles of drainage area. investigation because of its close proximity to the Uni- Land use and data analysis. The USGS Land Use and versity of Illinois and the Illinois Natural History Survey. Data Analysis (LUDA) data set contained within the Many detailed descriptions of the history, geography, IGIS represents land use and land cover for all of soils, climate, land use, and aquatic fauna have been Illinois. LUDA is based on a hierarchical classification reported (for example, Osborne and Wiley 1988; Wiley system developed nationally by the USGS for use with et al. 1990; Osborne et al. 1991; Tazik et al. 1991). remote sensor data (Anderson et al. 1976). The USGS derived land use and cover by conventional interpreta- Methodology tion of high-altitude color-infrared photographs onto The Illinois Geographic Information System (IGIS) base maps at a scale of 1:250,000. was the primary tool used to perform the work de- Data for the study area were extracted from this data Riparian Wildlife Habitat Evaluation 641 Figure 1. Stream names (with

Load more